1. A semi-intact preparation of the chick basilar papilla was developed to study calcium-dependent neurotransmitter release by tall hair cells (avian equivalent of cochlear inner hair cells). 2. Tall hair cell depolarization resulted in changes in cell membrane capacitance (DeltaC(m)) that reflected cell surface area increases following synaptic vesicle exocytosis and provided a surrogate measure of neurotransmitter release. Both calcium current (I(Ca)) and DeltaC(m) were reversibly blocked by cobalt, and exhibited a similar bell-shaped dependency on voltage with a peak response around -10 mV. 3. Pharmacological agents selective for L-type calcium channels were employed to assess the role of this channel type in neurotransmitter exocytosis. Nimodipine, a dihydropyridine (DHP) antagonist, suppressed I(Ca) and blocked DeltaC(m). Conversely, the DHP agonist Bay K 8644 increased both I(Ca) and DeltaC(m) amplitude nearly 3-fold. These findings suggest that chick tall hair cell neurotransmitter release is mediated by calcium influx through L-type calcium channels.
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http://dx.doi.org/10.1111/j.1469-7793.2001.00689.x | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
Department of Neurobiology, Harvard Medical School, Boston, MA 02115.
The sense of hearing originates in the cochlea, which detects sounds across dynamic sensory environments. Like other peripheral organs, the cochlea is subjected to environmental insults, including loud, damage-inducing sounds. In response to internal and external stimuli, the central nervous system directly modulates cochlear function through olivocochlear neurons (OCNs), which are located in the brainstem and innervate the cochlear sensory epithelium.
View Article and Find Full Text PDFArch Dermatol Res
January 2025
Institute of Pharmaceutical Research and Development, College of Pharmacy, Wonkwang University, Iksan, Jeonbuk, 54538, South Korea.
Hair follicle growth depends on the intricate interaction of cells within the follicle and its vascular supply. Current FDA-approved treatments like minoxidil have limitations, including side effects and the need for continuous use. Moracin M, a compound from Moraceae family, was investigated for its effects on hair growth and vascular regeneration.
View Article and Find Full Text PDFCurr Issues Mol Biol
January 2025
Beijing Key Laboratory of Plant Resources Research and Development, School of Light Industry Science and Engineering, Beijing Technology and Business University, Beijing 100048, China.
Hair loss is one of the skin conditions that can affect people's mental health. Plant raw material extracts are of great interest due to their safety. In this study, we utilize reverse network pharmacology to screen for key targets of the Wnt/β-catenin signaling pathway and the TGFβ/BMP signaling pathway, as well as key differential lipids, for plant raw materials selection.
View Article and Find Full Text PDFFront Pharmacol
January 2025
Department of Otolaryngology-Head and Neck Surgery, Affiliated Hospital of Jiangnan University, Wuxi, Jiangsu, China.
Objective: This research investigated the possible shielding properties of BB (Berberrubine) against the harmful auditory effects of cisplatin, preliminarily delving into the underlying mechanisms responsible for this protection.
Methods: HEI-OC1 cell viability was determined using a Cell Counting Kit-8 (CCK-8). The impact of BB on cochlear hair cells was studied through cochlear explants culture.
Hear Res
December 2024
Bionics Institute, East Melbourne, Victoria 3002, Australia; Department of Medical Bionics, The University of Melbourne, Fitzroy, Victoria 3065, Australia; Department of Surgery (Otolaryngology), University of Melbourne, The Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria 3002, Australia. Electronic address:
In the adult mammalian cochlea, hair cell loss is irreversible and causes deafness. The basic helix-loop transcription factor Atoh1 is essential for normal hair cell development in the embryonic ear. Over-expression of Atoh1 in the adult cochlea by gene therapy can convert supporting cells (cells that underlie hair cells) into a hair cell lineage.
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